WO2017182776A1

WO2017182776A1 - Filter arrangement

Info

Publication number: WO2017182776A1
Application number: PCT/GB2017/051028
Authority: WO
Inventors: Kevin Wood; Daniel HAMMETT; Daniel Stephen WRATTING
Original assignee: Momentum Bioscience Limited
Priority date: 2016-04-18
Filing date: 2017-04-12
Publication date: 2017-10-26

Abstract

A filter housing comprising: a filtration chamber defined as a volume enclosed by a pair of opposing sides and an edge, the filtration chamber having a filter support location extending in a plane intermediate the pair of opposing sides for accommodating a substantially planar filter. The filter housing further comprises an inlet conduit in fluid communication with the filtration chamber via an inlet aperture, wherein the inlet conduit projects from the edge of the filtration chamber at a first location at or proximate a first one of the pair of opposing sides. The filter housing further comprises an outlet conduit in fluid communication with the filtration chamber via an outlet aperture, wherein the outlet aperture projects from the edge of the filtration chamber at a second location at or proximate a second one of the pair of opposing sides. The inlet conduit and the outlet conduit are each substantially parallel to the plane.

Description

Filter arrangement

Background

In recent years there has been a move towards self-contained, disposable devices to facilitate diagnostic testing. Such devices are intended to enable samples to be processed outside a laboratory environment. Consequently, there is a need to be able to provide laboratory-type functionality in a compact manner that is suitable for a disposable device. In providing laboratory functionality in a self-contained, disposable device, that may be intended for only a single use, there is also an interest in reduced cost.

Summary

Against this background, there is provided a filter housing comprising:

a filtration chamber defined as a volume enclosed by a pair of opposing sides and an edge, the filtration chamber having a filter support location extending in a plane intermediate the pair of opposing sides for accommodating a substantially planar filter; an inlet conduit in fluid communication with the filtration chamber via an inlet aperture, wherein the inlet conduit projects from the edge of the filtration chamber at a first location at or proximate a first one of the pair of opposing sides; and

an outlet conduit in fluid communication with the filtration chamber via an outlet aperture, wherein the outlet aperture projects from the edge of the filtration chamber at a second location at or proximate a second one of the pair of opposing sides;

wherein the inlet conduit and the outlet conduit are each substantially parallel to the plane.

In this way, with the inlet and outlet conduits projecting from the edge of the filtration chamber, it is possible to provide a filter housing of a slimline arrangement that is particularly appropriate for incorporation into a compact, durable and disposable cartridge arrangement.

The inlet aperture may be located in the first one of the pair of opposing sides and the outlet aperture may be located in the second one of the pair of opposing sides. In this way, each of the pair of opposing sides may be a mirror image of the other for straightforward construction. The filtration chamber may be substantially disc-shaped and the edge may be substantially cylindrical.

In this way, the filtration chamber may accommodate a disc-shaped filter. The inlet aperture may be located at or towards a first peripheral location of the discshaped filtration chamber and the outlet aperture is located at or towards a second peripheral location of the disc-shaped filtration chamber.

In this way, with the inlet and outlet apertures at different peripheral locations, a net direction of flow of fluid through the filter support location may be influenced. This may be chosen to make most efficient use of the filter.

The inlet conduit and the outlet conduit may be mutually parallel or substantially mutually parallel.

In this way, for example, the inlet and outlet conduits may both be directed towards one end of a cartridge in which the filter housing is accommodated such that fluid connections may be grouped in one location. The filter housing may comprise a plinth configured to support the filter housing in a support plane in an orientation of use such that the filter support location lies in a filter plane that is perpendicular, or substantially perpendicular, to the support plane.

This is because the filter housing is particularly appropriate for mounting in a plane wherein, in the orientation of use, gravity does not act coincident with a direction of flow through the plane of the filter or or in a direction opposite to a direction of flow through the plane of the filter.

One or both of the inlet and outlet conduits may be parallel to the filter plane. In this way, a particularly compact arrangement is realisable.

The inlet aperture may be located in a portion of the filter housing closest to the plinth. The outlet aperture may be located in a portion of the filter housing furthest from the plinth.

The filter housing may comprise a diagonal channel between the outlet aperture and the outlet conduit. In this way, the inlet and outlets may be offset relative to the edge of the filter housing.

The pair of opposing sides may comprise a plurality of recesses and/or protrusions that are configured to facilitate flow of fluid within the filtration chamber from a vicinity of the inlet aperture and towards a vicinity of the outlet aperture.

In this way, the recesses and/or protrusions may serve a dual purpose of supporting the filter in position within the filtration chamber whilst enabling efficient flow of fluid through the filter. In a further aspect of the disclosure there may be provided a multi-channel filtration device comprising a plurality of filter housings as disclosed herein wherein the filter support location of each filter housing is parallel to the filter support location of each other filter housing. In this way, a particularly space-efficient multi-channel filtration device is achievable.

The multi-channel filtration device may be configured such that the inlet conduit of each filter housing is parallel to the inlet conduit of each other filter housing. In this way, a particularly space-efficient multi-channel filtration device is achievable.

The multi-channel filtration device may be configured such that the outlet conduit of each filter housing is parallel to the outlet conduit of each other filter housing. In this way, a particularly space-efficient multi-channel filtration device is achievable. The filter assembly may comprise a plurality of filter housings.

Further aspects

Further aspects of the disclosure are set forth in the following numbered clauses:

1.1. A filtration device comprising:

a first reservoir for fluid;

a plurality of channels configured to operate in parallel, each channel comprising: a primary filtration chamber having a primary filtration chamber inlet, a primary filtration chamber outlet and a primary filter support location that extends substantially in a primary filtration plane for accommodating a substantially planar filter; and a syringe having a syringe actuator movable in a syringe axis and configured to transfer fluid from the first reservoir to the primary filtration chamber via the primary filtration chamber inlet; and

a supply valve having an open position in which fluid communication between the first reservoir and the plurality of channels is enabled and having a closed position in which fluid communication between the first reservoir and the plurality of channels is prevented; wherein the primary filtration plane of each channel is parallel to the primary filtration plane of each other channel.

1.2. The filtration device of clause 1.1 wherein the primary filtration chamber of each channel is aligned with the primary filtration chamber of each other channel.

1.3. The filtration device of clause 1.1 or clause 1.2 wherein the syringe axis of each channel is parallel to the filtration plane.

1.4. The filtration device of clause 1.1 of clause 1.2 wherein the syringe axis of each channel lies in the filtration plane.

1.5. The filtration device of any preceding clause wherein the syringe axis of each channel is parallel to the syringe axis of each other channel of the plurality of channels. 1.6. The filtration device of clause 1.5 comprising a syringe plane wherein the syringe axis of each channel sits in the syringe plane.

1.7. The filtration device of any preceding clause wherein the supply valve comprises an actuator that is moveable in a supply valve axis between the open position of the supply valve and the closed position of the supply valve, and wherein the supply valve axis is neither coincident with nor parallel to the syringe axis of each of the channels.

1.8. The filtration device of clause 1.7 wherein the supply valve axis is perpendicular to the syringe axis of each of the channels.

1.9. The filtration device of any preceding clause further comprising a plinth configured to support the filtration device in a support plane in an orientation of use.

1.10. The filtration device of clause 1.9 wherein the primary filtration plane of each channel is perpendicular to the support plane.

1.11. The filtration device of clause 1.9 or clause 1.10 wherein the syringe of each of the plurality of channels is located within the plinth of the filtration device.

1.12. The filtration device of clause 1.9 or any clause dependent on clause 1.9 wherein the syringe axis of each syringe is parallel to the support plane.

1.13. The filtration device of clause 1.9 or any clause dependent on clause 1.9 wherein each primary filtration chamber inlet is located in a portion of the primary filtration chamber closest to the plinth of the filtration device.

1.14. The filtration device of clause 1.9 or any clause dependent on clause 1.9 wherein each primary filtration chamber outlet is located in a portion of the primary filtration chamber furthest from the plinth of the filtration device.

1.15. The filtration device of any preceding clause wherein the primary filter support location of each channel comprises a plurality of recesses and/or protrusions that are configured to facilitate flow of fluid within the primary filtration chamber from a vicinity of the primary filtration chamber inlet and towards a vicinity of the primary filtration chamber outlet.

1.16. The filtration device of any preceding clause further comprising a channel outlet for each channel and a waste chamber common to all channels,

and wherein each channel of the filtration device further comprises one or more downstream valves configured to direct filtered fluid either to the channel outlet or to the waste chamber. 1.17. The filtration device of clause 1.16 wherein the waste chamber comprises a thermal interface region configured to enable transfer of thermal energy into the waste chamber.

1.18. The filtration device of clause 1.16 wherein each primary filtration chamber is located within the waste chamber.

1.19. The filtration device of any preceding clause further comprising:

a second reservoir for fluid; and

a reservoir valve arrangement configured to close fluid communication between the first reservoir and the syringe and to open fluid communication between the second reservoir and the syringe of each channel.

1.20. The filtration device of clause 1.19 further comprising one or more further reservoirs for fluid and wherein the reservoir valve arrangement is configured to enable fluid communication between one of the first, second and further reservoirs and the syringe of each channel.

1.21. The filtration device of any preceding clause further comprising a supply valve actuator, the supply valve actuator being configured to effect movement of the supply valve of each channel between a closed supply valve actuator position in which the supply valve of each channel is closed and an open supply valve actuator position in which the supply valve of each channel is open.

1.22. The filtration device of clause 1.21 when dependent on clause 1.9 or any clause dependent on clause 1.9 wherein, in the closed supply valve actuator position, the supply valve actuator is contained within a volume bounded by the plinth. 1.23. The filtration device of clause 1.22 wherein, in the open supply valve actuator position, the supply valve actuator projects beyond the volume bounded by the plinth. 1.24. The filtration device of clause 19 or any clause dependent on clause 1.19 wherein the reservoir valve arrangement comprises one or more reservoir valve actuators and wherein one or more of the reservoir valve actuators is contained within a volume bounded by the plinth when in a closed position and projects beyond the volume bounded by the plinth when in an open position.

1.25. The filtration device of clause 1.16 or any clause dependent on clause 1.16 wherein the one or more downstream valves comprises one or more downstream valve actuators and wherein one or more of the downstream valve actuators is contained within a volume bounded by the plinth when in an open position and projects beyond the volume bounded by the plinth when in a closed position.

1.26. The filtration device of clause 1.11 or any clause dependent on clause 1.11 wherein the syringe actuator of each syringe is movable between an inward position and an outward position and wherein:

in the inward position, the syringe actuator is contained within a volume bounded by the plinth; and

in the outward position, the syringe actuator projects beyond the volume bounded by the plinth. 1.27. The filtration device of clause 1.16 wherein the channel outlets for each channel are contained within a volume bounded by the plinth such that when the plinth rests on a planar surface the channel outlets terminate at a distance from said planar surface.

1.28. The filtration device of any preceding clause further comprising, for each channel, a mixing chamber downstream of the first reservoir and upstream of the filtration chamber inlets.

1.29. The filtration device of clause 1.28 wherein the mixing chamber comprises a sample inlet to allow a sample to be inserted into the mixing chamber for mixing with a reagent prior to passing into the primary filtration chamber. 1.30. The filtration device of clause 1.28 further comprising a pre-filter upstream of the primary filtration chamber to prevent passage of material larger than pores of the pre-filter from passing into the primary filtration chamber, wherein either:

(a) the pre-filter is upstream of the mixing chamber: or

(b) the pre-filter is immediately downstream of the mixing chamber.

1.31. The filtration device of any preceding clause wherein the first reservoir comprises a vent hole to allow gas to enter the first reservoir such that when fluid passes out of the first reservoir to the syringe of each channel a pressure within the first reservoir may remain constant.

1.32. The filtration device of any preceding clause further wherein each channel further comprises a secondary filtration chamber downstream of the primary filtration chamber.

1.33. The filtration device of clause 1.32 wherein the secondary filtration chamber of each channel comprises a secondary filtration chamber inlet and the primary filtration chamber outlet is in fluid communication with the secondary filtration chamber inlet. 1.34. The filtration device of clause 1.32 or clause 1.33 when dependent on clause 1.16 or any clause dependent on clause 1.16 wherein the secondary filtration chamber of each channel comprises a secondary filtration chamber outlet in fluid communication with the one or more downstream valves such that the filtered fluid that is directed either to the channel outlet or to the waste chamber is has passed through both the primary and secondary filtration chambers.

1.35. The filtration device of clause 1.33 when dependent on clause 1.9 or any clause dependent on clause 1.9 wherein, for each channel, the secondary filtration chamber inlet is located in a portion of the primary filtration chamber closest to the plinth of the filtration device.

1.36. The filtration device of clause 1.35 wherein each channel further comprises a diagonal channel configured to convey fluid between the primary filtration chamber outlet and the secondary filtration chamber inlet. 1.37. The filtration device of clause 1.36 wherein for each channel the secondary filtration chamber outlet is located in a portion of the secondary filtration chamber furthest from the plinth of the filtration device. 1.38. The filtration device of any of clauses 1.32 to 1.37 wherein each secondary filtration chamber comprises a secondary filter support location that extends substantially in a secondary filtration plane for accommodating a substantially planar second filter.

1.39. The filtration device of any of clauses 1.32 to 1.38 wherein the secondary filtration chamber is laterally offset from the primary filtration chamber.

1.40. The filtration device of clause 1.39 wherein, for each channel, the secondary filtration plane is parallel to the primary filtration plane. 1.41. The filtration device of clause 1.39 wherein, for each channel, the secondary filtration plane and the primary filtration plane are the same.

2.1. A device for conducting a chemical reaction, the device comprising:

a reaction chamber bounded at least in part by a thermally conductive wall, the reaction chamber having a reaction chamber access aperture; and

a reservoir having an energy transfer element configured to facilitate transfer of energy from outside the reservoir to inside the reservoir for affecting a temperature within the reservoir;

wherein the reaction chamber is located within the reservoir and wherein the reaction chamber access aperture is fluidly connected to the reservoir.

2.2. The device of clause 2.1 wherein the energy transfer element comprises an interface for enabling transfer of thermal energy from an external surface of the reservoir to an internal surface of the reservoir.

2.3. The device of clause 2.1 wherein the energy transfer element comprises a region transparent to infra-red radiation configured to enable transmission of energy into the reservoir. 2.4. The device of clause 2.1 wherein the energy transfer element comprises a metallic conductor configured to receive electro-magnetic energy by electro-magnetic induction.

2.5. The device of any of clauses 2.1 to 2.4 wherein the reaction chamber access aperture is fluidly connected to the reservoir via a transit conduit.

2.6. The device of clause 2.5 wherein the reservoir comprises a reservoir floor and a reservoir wall, and wherein the reservoir wall comprises the transit conduit. 2.7. The device of clause 2.6 wherein, in an orientation of use, the reservoir floor is horizontal or substantially horizontal and the reservoir wall is vertical or substantially vertical.

2.8. The device of clause 2.6 or clause 2.7 wherein, in an orientation of use, the access aperture is located at or towards a top edge of the reservoir wall.

2.9. The device of clause 2.5 or any clause dependent upon clause 2.5 wherein the reaction chamber access aperture comprises an open end of the transit conduit. 2.10. The device of clause 2.9 wherein the access aperture further comprises a notch in a side wall of the transit conduit that extends from the open end of the transit conduit.

2.11. The device of clause 2.10 wherein the notch in the side wall faces towards the reaction chamber.

2.12. The device of any of clauses 2.1 to 2.1 1 further comprises an overflow container configured, in an orientation of use, to receive fluid via a fluid overflow route from the reservoir. 2.13. The device of clause 2.12 wherein, in the orientation of use, a lowest part of the fluid overflow route is above or coincident with a highest part of the reaction chamber.

2.14. The device of clause 2.12 or clause 2.13 when dependent upon clause 9 wherein, in the orientation of use, the fluid overflow route is below or coincident with the open end of the transit conduit. 2.15. The device of any of clauses 2.1 to 2.14 wherein the reaction chamber comprises a filter support location for accommodating a substantially planar filter. 2.16. An assembly comprising the device of any of clauses 2.1 to 2.15 and:

one or more than one further reaction chamber each bounded at least in part by a thermally conductive wall, and each further reaction chamber having a reaction chamber access conduit aperture;

wherein the reaction chamber access aperture of some or all of the further reaction chambers is fluidly connected to the reservoir.

2.17. A method of using the device of any of clauses 2.1 to 2.15 or the assembly of clause 2.16, the method comprising:

supplying a plurality of reactants to the reaction chamber;

enabling a first chemical reaction to take place in the reaction chamber;

moving at least some of the contents of the reaction chamber out of the reaction chamber via the reaction chamber access aperture and into the reservoir;

applying energy to the energy transfer element in order to control a temperature of the contents of the reservoir;

enabling a second chemical reaction to take place in the reaction chamber.

2.18. The method of clause 2.17 further comprising the step of supplying one or more further reactants to the reaction chamber prior to enabling the second chemical reaction to take place in the reaction chamber.

Brief description of the drawings

Embodiments of the disclosure will now be described with reference to the following drawings in which:

Figure 1 shows a perspective view of a first embodiment of the disclosure with a top side facing up; Figure 2 shows a perspective view of the first embodiment with an underside facing up; Figure 3 shows a schematic representation of a first part of the first embodiment; Figure 4 shows a schematic representation of a second part of the first embodiment;

Figure 5 shows a cross section through the first embodiment with a top side facing up;

Figure 6 shows a cross section through the first embodiment with an underside facing up; Figure 7 shows a perspective view of an interior of the first embodiment of the disclosure;

Figure 8 shows a perspective view, similar to Figure 2, of the first embodiment but with some of the components removed; Figure 9 shows a perspective view, similar to Figure 2, of the first embodiment but with still further components removed;

Figure 10 shows a cross-section through the first embodiment perpendicular to a net direction of flow of fluid within the device with an underside facing up;

Figure 11 shows a perspective view of a filter assembly of the first embodiment;

Figure 12 shows a perspective view of an interior of the filter assembly of the first embodiment;

Figure 13 shows the filter assembly of the Figure 1 1 inverted;

Figure 14 shows the filter assembly of the Figure 12 inverted; Figure 15 shows a cross section through the filter assembly of Figure 1 1

Figure 16 shows a perspective view of the interiors of eight filter assemblies of the first embodiment in parallel; Figure 17 shows half of the filter assembly of Figure 1 1 ; Figure 18 shows a similar view to Figure 17 but with one component removed to reveal a fluid channel; Figure 19 shows a side view of the filter assembly of Figure 11 ;

Figure 20 shows the filter assembly of Figure 11 with internal components shown in broken lines; Figure 21 shows a cross section through the filter assembly of Figure 1 1 ;

Figure 22 shows a further cross section through the filter assembly of Figure 11 ;

Figure 23 shows a schematic representation of a variation of the first embodiment that corresponds to that shown in Figure 4;

Figure 24 shows a perspective view of a second embodiment of the disclosure with a top side facing up (cf. Figure 1); Figure 25 shows a cross section through the second embodiment with a top side facing up (cf. Figure 5);

Figure 26 shows a cross section through the second embodiment with an underside facing up (cf. Figure 6);

Figure 27 shows a perspective view of an interior of the second embodiment of the disclosure (cf. Figure 7);

Figure 28 shows a perspective view of the second embodiment with components removed (cf. Figure 9);

Figure 29 shows a perspective view of a filter assembly of the second embodiment (cf. Figure 1 1); Figure 30 shows a perspective view of the interiors of eight filter assemblies of the second embodiment in parallel (cf. Figure 16); and

Figure 31 shows a schematic representation of the second embodiment (cf. Figure 4).

Detailed description

Filter cartridge of a first embodiment

A first embodiment of a filter cartridge 100 in accordance with the invention is illustrated in Figures 1 and 2. This embodiment comprises eight independent channels (a, b, c, d, e, f, g, h) for analysing eight samples. Functionally, the filter cartridge comprises 100: a reagent supply assembly 500 which is common to all eight channels (and shown in a highly schematic fashion in Figure 3); and eight analysis assemblies 600, one for each channel (one analysis assembly is shown in a highly schematic fashion in Figure 4). In this description, when discussing a particular one of the eight channels, the reference numeral for the component is appended with a reference letter (a, b, c, d, e, f, g, h) for that channel. However, since the features of each channel are the same as the features of each of the other seven channels, when discussing generic aspects of the channels (rather than aspects relating to one particular channel), reference numerals are not appended by the letter for a particular channel.

Referring again to Figures 3 and 4, each of the eight conduits 571 , 572, 573, 574, 575, 576, 577, 578 at the far right hand side of the schematic representation of Figure 3 is connected to the left-most inlet 61 1a, 61 1 b, 611 c, 611d, 611 e, 61 1f, 611 g, 61 1 h of an analysis assembly 600 illustrated schematically in Figure 4.

The reagent supply assembly 500 comprises a first reagent reservoir 510, a second reagent reservoir 520, a third reagent reservoir 530 and a fourth reagent reservoir 540. The reservoirs are shown in the first embodiment in Figure 7 and are shown more schematically in Figure 3. Each of the first to fourth reagent reservoirs comprises an inlet conduit 51 1 , 521 , 531 , 541. A first end of each of the first to fourth inlet conduits 511 , 521 , 531 , 541 comprises a fill port 512, 522, 532, 542 while a second end of each of the first to fourth inlet conduits 511 , 521 , 531 , 541 is fluidly connected to the first to fourth reagent reservoirs 510, 520, 530, 540, respectively.

The reagent supply assembly 500 further comprises first to fourth reservoir vents 515, 525, 535, 545, one for each of the first to fourth reagent reservoirs 510, 520, 530, 540. The first to fourth reservoir vents 515, 525, 535, 545 serve to allow release of gas (e.g. air) from the respective first to fourth reagent reservoirs 510, 520, 530, 540, for example when displaced by fluid that enters the first to fourth reagent reservoirs 510, 520, 530, 540 via the respective first to fourth inlet conduits 511 , 521 , 531 , 541. The first to fourth reservoir vents 515, 525, 535, 545 serve to allow gas (e.g. air) to pass into the respective first to fourth reagent reservoirs 510, 520, 530, 540, for example when fluid is drawn out of the first to fourth reagent reservoirs 510, 520, 530, 540 to locations downstream within the reagent supply assembly 500.

Each of the first to fourth reagent reservoirs 510, 520, 530, 540 comprises a reservoir outlet 513, 523, 533, 543. Each of the first to fourth reservoir outlets 513, 523, 533, 543 is, respectively, connected to a first to fourth reservoir supply line 514, 524, 534, 544.

The reagent supply assembly 500 further comprises a selector valve 550. The selector valve 550 comprises four inlets and one outlet. Each of the four inlets receives one of the first to fourth reservoir supply lines 514, 524, 534, 544. The selector valve 550 is configured such that it can receive fluid from only one or none of the first to fourth reservoir supply lines 514, 524, 534, 544. A selector valve outlet conduit 560 provides an outlet from the selector valve 550.

The branch conduit assembly 561 (shown in the first embodiment in Figure 8 and more schematically in Figure 3) divides the output from the selector valve 550 into first to eighth channel supply conduits 571 , 572, 573, 574, 575, 576, 577, 578. Each of these first to eighth channel supply conduits 571-578 is configured to supply reagent to one of the first to eight channels (a, b, c, d, e, f, g, h) of the filter cartridge 100.

Each of the eight channels (a, b, c, d, e, f, g, h) may be the same in terms of form and function as each of the other eight channels. Accordingly, for the sake of clarity, the schematic representation in Figure 4 shows only a single channel. In the filter cartridge 100, the form and function of this channel (channel a) is repeated seven times to provide the remaining channels b, c, d, e, f, g, h. Referring to Figure 4, each channel comprises an analysis assembly 600 that comprises a mixing chamber 620, a syringe 630, a filter assembly 640 and a sample outlet 690.

Furthermore, the filter cartridge 100 comprises a combined waste chamber fluid bath 150 configured to be operable as a fluid bath in which all of the filter assemblies 640a - 640h are located.

The mixing chamber 620 comprises a sample inlet 621 and a sample inlet filter assembly 622. The sample inlet filter assembly 622 is configured to receive a sample inlet filter 623.

The syringe 630 comprises a syringe housing 631 , a syringe member 632, a syringe actuator 633 and a syringe access port 635. The syringe member 632 comprises a syringe member face 634 that may be surrounded by a circumferential O-ring or similar so as to provide an air-fluid-tight seal between the O-ring or similar of the syringe member face 634 and an interior of the syringe housing 631. The syringe member 632 is located coaxially within the syringe housing 631 and the syringe actuator 633 facilitates movement of the syringe member 632 in an axial direction relative to the syringe housing 631. The syringe member 632 comprises a syringe member face 634 that is a part of the syringe member 632 that is located closest to the syringe access port 635 and, when moved in an axial direction, acts to draw fluid into or out of the syringe housing 631. The filter assembly 640 comprises a first filter housing 641 and a second filter housing 642. The first filter housing 641 may be configured to receive a first filter 643 comprising a first grade filtration material. The second filter housing 642 may be configured to receive a second filter 644 having a filter material comprising a second grade filtration material. The first filter 643 may prevent passage of relatively larger materials while the second filter 644 may prevent passage of relatively smaller materials. Since the first filter housing is located upstream of the second filter housing, this provides a two-stage filtration capability. By separating the filtration capability into two, this may reduce likelihood of clogging of filtration materials. As shown in Figure 4, the filter assembly 640 of all of the eight channels (a - h) is surrounded by a single waste chamber fluid bath 150 that is configured to receive fluid that passes downstream of the filter assembly 640 of all eight channels (a - h). The waste chamber fluid bath 150 comprises a thermal interface region 160 through which heat may be transferred in order to control a temperature of fluid within the eight filter assemblies 640a - 640h. By surrounding the eight filter assemblies by the waste chamber fluid bath 150, the waste chamber fluid bath 150 serves the dual purpose of (a) receiving fluid that has passed out of the filter assemblies 640a - 640h and (b) providing a volume of fluid that surrounds the filter assemblies 640a - 640h and can thereby be used to control a temperature of fluid present in the filter assemblies 640a - 640h at a later stage. By providing a single waste chamber fluid bath 150 for all eight channels (rather than one for each) this increases the likelihood of all eight channels being at the same temperature.

A plurality of conduits 61 1 , 612, 613, 614, 615, 616 is configured to facilitate flow of fluid between various of the previously described components of the analysis assembly 600, as discussed in more detail below.

A first conduit 61 1 is configured to receive fluid from one of the first to eighth channel supply conduits 571 , 572, 573, 574, 575, 576, 577, 578 of the reagent supply assembly 500. The first conduit 61 1 comprises an analysis assembly entry valve 673 at an upstream end of the first conduit 611 which allows or prevents flow of fluid downstream of the analysis assembly entry valve 673. Downstream of the analysis assembly entry valve 673, a second conduit 612 branches from the first conduit 61 1 and, still further downstream of the analysis assembly entry valve 673, a third conduit 613 branches from the first conduit 61 1. A filter assembly valve 674 is located in the first conduit 61 1 downstream of the third conduit 613. The filter assembly valve 674 either allows or prevents flow of fluid downstream of the filter assembly valve 674.

Downstream of the filter assembly valve 674 is located the filter assembly 640 such that an outlet of the first conduit 61 1 flows into an inlet of the filter assembly 640. An outlet of the filter assembly 640 is connected to an inlet of a fourth conduit 614. The fourth conduit 614 bifurcates to form a fifth conduit 615 and a sixth conduit 616.

The second conduit 612 provides a fluid connection between the first conduit 61 1 and the mixing chamber 620. A mixing chamber valve 672 is located in the second conduit 612 upstream of the mixing chamber 620 and is configured to allow or prevent flow of fluid into and out of the mixing chamber 620.

The third conduit 613 is configured to connect the first conduit 611 to the syringe access port 635.

The fifth conduit 615 is configured to connect the fourth conduit 614 to the waste chamber fluid bath 150. In the fifth conduit 615, upstream of the waste chamber fluid bath 150, is a waste chamber valve 675. The waste chamber valve 675 is configured to allow or prevent flow of fluid into the waste chamber fluid bath 150. As mentioned previously, the waste chamber fluid bath 150 is a single waste chamber fluid bath 150 shared by all channels (a - h). Each channel (a - h) has its own waste chamber valve 675a - 675h. Downstream of each waste chamber valve 675a - 675h, each fifth conduit 615a - 615h opens into the single waste chamber fluid bath 150.

The sixth conduit 616 is configured to connect the fourth conduit 614 to a sample outlet 690. The sixth conduit 616 comprises an outlet valve 676 upstream of the sample outlet 690. The outlet valve 676 is configured to allow or prevent flow of fluid into the sample outlet 690. In use, a receptacle 691 may be placed adjacent the sample outlet 690 so as to receive fluid that may be passed out of the sample outlet 690.

While it is not apparent from Figure 4, it is to be noted with reference to Figures 1 and 2 that the mixing chamber valve 672 of each channel (a - h) is operationally connected to the mixing chamber valve of each of the other channels (a - h). As such, when the mixing chamber valve 672a of first channel (channel a) is open, the other mixing chamber valves (672b - 672h) - those in each and all of the other seven channels (b to h) - are also open. The eight mixing chamber valves 672a - 672h are controlled by a single valve actuator, namely the second valve actuator 1 12, visible in Figures 1 and 2. Similarly, the analysis assembly entry valve 673a of the first channel is operationally connected to the analysis assembly entry valve 673b - 673h for all of the seven other channels. As such, the eight analysis assembly entry valves 673a - 673h are controlled by a single valve actuator, namely the third valve actuator 1 13. Similarly again, the filter assembly valve 674a of the first channel is operationally connected to the filter assembly valve 674b - 674h of all of the other seven channels. As such, the eight filter assembly valves 674a - 674h are controlled by a single valve actuator, namely the fourth valve actuator 1 14.

Similarly again, the waste chamber valve 675a of the first channel is operationally connected to the waste chamber valve 675b - h of all of the other seven channels. As such, the eight waste chamber valves 675a - 675h are controlled by a single valve actuator, namely the fifth valve actuator 115.

Finally, the outlet valve 676a of the first channel is operationally connected to the outlet valve 676b - 676h of all of the other seven channels. As such, the eight outlet valves 676a

- 676h are controlled by a single valve actuator, namely the sixth valve actuator 116. In this way, all channels (a - h) are operable simultaneously in parallel. Indeed, it is not possible to actuate the valves of one channel without simultaneously operating the corresponding valve of every other channel.

Returning to Figure 1 , the filter cartridge 100 of the first embodiment comprises a filter cartridge housing 101 having a reagent supply assembly 500 as shown schematically in Figure 3 and eight analysis assemblies 600 as shown in Figure 4, one for each channel (a

- h). A first valve actuator 11 1 is configured to control the position of the selector valve 550 of the reagent supply assembly 500. In a first position of the first valve actuator 11 1 , the selector valve 550 is closed to all four supply lines 514, 524, 534, 544. In a second position, the selector valve 550 is open only to first reservoir supply line 514 and the selector valve outlet conduit 560 such that only the first reservoir supply line 514 is fluidly connected to the selector valve outlet conduit 560. In a third position, the selector valve 550 is closed. In a fourth position, the selector valve 550 is open only to the second reservoir supply line 524 and the selector valve outlet conduit 560 such that only the second reservoir supply line 524 is fluidly connected to the selector valve outlet conduit 560. In a fifth position, the selector valve 550 is closed. In a sixth position, the selector valve 550 is open only to the third reservoir supply line 534 and the selector valve outlet conduit 560 such that only the third reservoir supply line 534 is fluidly connected to the selector valve outlet conduit 560. In a seventh position, the selector valve 550 is closed. In an eighth position, the selector valve 550 is open only to the fourth reservoir supply line 544 and the selector valve outlet conduit 560 such that only the fourth reservoir supply line 544 is fluidly connected to the selector valve outlet conduit 560. In a ninth position the selector valve 550 is closed. The first valve actuator 11 1 is moveable in and out of the filter cartridge housing 101 , sequentially between the first and the ninth positions. In the first position of the first valve actuator 1 1 1 , the first valve actuator 11 1 is in an inmost position relative to the filter cartridge housing 101 , as shown in Figure 1.

The second valve actuator 112 is configured to control the mixing chamber valve 672 of all of the eight channels (a - h) in parallel. The third valve actuator 113 is configured to control the analysis assembly entry valve 673 of all of the eight channels (a - h) in parallel. The fourth valve actuator 1 14 is configured to control the filter assembly valve 674 of all of the eight channels (a - h) in parallel. The fifth valve actuator 115 is configured to control the position of the waste chamber valve 675 of all of the eight channels (a - h) in parallel. Finally, the sixth valve actuator 116 is configured to control the position of the outlet valve 676 of all of the eight channels (a - h) in parallel. In this way, each of the second to sixth valve actuators 1 12 - 1 16 has a closed position in which the respective valve of each channel (a - h) is closed and an open position in which the respective valve of each channel (a - h) is open. Each of the second to sixth valve actuators comprises eight valve conduits, each spaced apart the same distance as the spacing of the eight channels (a - h). Between each of the eight valve conduits is provided a barrier which, when the actuator is closed, closes off each of the eight channels (a - h). Accordingly, it is not possible to control any of the mixing chamber valve 672, the analysis assembly entry valve 673, the filter assembly valve 674, the waste chamber valve 675 and outlet valve 676 of one channel without controlling that corresponding valve in respect of all of the other seven channels.

In the first embodiment, the open position of the second, fourth, fifth and sixth valve actuators 1 12, 1 14, 1 15, 1 16 corresponds to an inmost position relative to the filter cartridge housing 101 whilst the closed position of the third valve actuator 113 corresponds to an inmost position relative to the filter cartridge housing 101. Furthermore, the first position of the first valve actuator 11 1 , in which the first valve is closed to all four supply lines 514, 524, 534, 544, corresponds to an inmost position of first valve actuator 1 1 1 relative to the filter cartridge housing 101 , as shown in Figure 1. In this way, when all valve actuators 11 1 - 1 16 are in the inmost position (such as when shipped prior to use), only the first and third valve actuators 1 11 , 1 13 are closed. This prevents flow of fluid out of the first to fourth reagent reservoirs 510, 520, 530, 540 and also prevents flow of fluid into any of the eight analysis assemblies 600a - 600h since the analysis assembly entry valves 673a - 673h are closed. The remaining valve actuators (that is the second, fourth, fifth and sixth valve actuators 1 12, 1 14, 1 15, 116) are open. In this way, all of the mixing chamber valves 672a - 672h, the filter assembly valves 674a - 374h, the waste chamber valves 675a - 375h and the outlet valves 676a - 676h are open which means that the cartridge is allowed to equalise to atmospheric pressure. This may be particularly useful during transit when the filter cartridge 100 might experience a wide range of atmospheric pressures.

Having discussed the reagent supply assembly 500 and a single analysis assembly 600 with reference to the schematic illustrations in Figures 3 and 4, the packaging of those features is now discussed in relation to the embodiment of filter cartridge illustrated in Figures 1 and 2.

Referring to Figure 1 , the reagent supply assembly 500 is towards the left side of the Figure while the eight parallel channels a - h, each comprising an analysis assembly 600, are largely towards the right side of the Figure. The eight syringes 630a - 630h, one for each channel, are located beneath the reagent supply assembly 500, as shown in Figure 2. The overall form of the filter cartridge 100 is substantially rectangular, forming a

substantially rectangular silhouette.

The filter cartridge 100 comprises a filter cartridge housing 101 and a filter cartridge plinth 102 located at a perimeter of a lower surface of the filter cartridge housing 101 on which the cartridge is supported when resting on a planar surface in the orientation shown in Figure 1.

In its initial configuration, as illustrated in Figures 1 and 2, the moveable and/or more delicate components of the filter cartridge 100 are all located within the substantially rectangular silhouette. For example, the first to sixth valve actuators 1 11 , 112, 113, 114, 1 15, 1 16 are located within recesses 141 , 142, 143, 144, 145, 146 in the filter cartridge plinth 102 relative to the overall rectangular silhouette of the filter cartridge. In this way, in their initial positions, the valve actuators 1 11 , 1 12, 1 13, 1 14, 1 15, 1 16 do not extend outside the substantially rectangular silhouette.

The first to sixth valve actuators 11 1 , 112, 113, 114, 115, 116 are configured to move in first to sixth valve actuator axes, respectively. Each of the first to sixth valve actuator axes is mutually parallel and all of the first to sixth valve actuator axes sit in a single valve actuator plane.

Located in a volume within the filter cartridge plinth 102 are the eight syringes 630a - 630h as well as the eight sample outlets 690a - 690h. The filter cartridge plinth 102 is interrupted on a side of the filter cartridge 100 closest to the syringe actuators 633a - 633h so as to allow access to the syringe actuators 633a - 633h when the plinth 102 of the filter cartridge 100 is resting on a planar surface. The first to eighth syringes 630a - 630h are configured to move in first to eighth syringe axes, respectively. Each of the first to eighth syringe axes is mutually parallel and all of the first to eighth syringe axes sit in a single syringe plane.

The syringe plane is coincident with or parallel to the valve actuator plane. The first to eighth syringe axes are mutually perpendicular to the first to sixth syringe axes.

The height of the six sample outlets 690a - 690h is less than the height of the plinth 102 such that, when the filter cartridge plinth 102 is resting on a planar surface, the sample outlets 690a - 690h sit above, rather than making contact with, the planar surface. This not only reduces risk of physical damage to the sample outlets 690a - 690h but also reduces risk of contamination.

Also evident in Figure 2 is the thermal interface region 160 discussed previously with respect to the schematic representation of Figure 4. The thermal interface region 160 is in the form a recessed region on an underside of the filter cartridge housing 101 within the boundaries of the filter cartridge plinth 102. The recessed region that forms the thermal interface region 160 may comprise a thinner wall of the filter cartridge housing 101 than a wall of the filter cartridge housing 101 that surrounds the interface region 160. The thinner portion of wall being recessed relative to a surrounding thicker section of wall may itself facilitate thermal transfer. The recess may be on the inner or the outer face of the wall of the filter cartridge housing 101. If the recess is on the outer face of the wall of the filter cartridge housing 101 , this may also provide assistance in alignment with an external heat source which it is configured to receive. An external heat source may be used to transfer heat via the interface region 160 into the waste chamber fluid bath 150 located within the interior of the filter cartridge housing 101. The location of the waste chamber fluid bath 150 within the filter cartridge housing 101 is visible in Figure 5, which shows a cross-section through the filter cartridge 100.

On a top face of the filter cartridge housing 101 , as shown in Figure 1 , are located the first, second, third and fourth fill ports 512, 522, 532, 542 that protrude above a top surface of the filter cartridge housing 101 and which provide access to, respectively, first, second, third and fourth inlet conduits 51 1 , 521 , 531 , 541. The first, second, third and fourth fill ports 512, 522, 532, 542 are fluidly connected, respectively, to the first, second, third and fourth reagent reservoirs 510, 520, 530, 540 within the filter cartridge housing 101.

First, second, third and fourth inlet conduits 51 1 , 521 , 531 , 541 may each comprise a oneway valve, seal and/or gasket (not shown) to prevent a reagent that may be present in the respective reagent reservoirs 510, 520, 530, 540 from being released from the cartridge, for example under the effect of gravity if the filter cartridge 100 is inverted such that the first, second, third and fourth inlet conduits 511 , 521 , 531 , 541 face downwards.

Similarly, first to eighth sample inlets 621a - 621 h protrude above a top surface of the filter cartridge housing 101 and allow each of eight samples to be deposited into each of the eight channels (a - h) of the filter cartridge 100. The first to eighth sample inlets 621a - 621 h are fluidly connected, respectively, to the mixing chamber 620a - 620h via, respectively, first to eighth sample inlet filter assemblies 622a - 622h. Each of the first to eighth sample inlet filter assemblies 622a - 622h comprises a sample inlet filter 623a - 623h configured to prevent passage of particles larger than those that would be appropriate for processes intended to take place in the filter cartridge 100.

The top surface of the filter cartridge housing 101 also comprises the first reservoir vent 515, second reservoir vent 525, third reservoir vent 535 and fourth reservoir vent 545, one for each of the first, second, third and fourth reagent reservoirs 510, 520, 530, 540, respectively. As previously mentioned, the purpose of the vents may be two-fold. First, the vents allow gas (e.g. air) to vent out of each reservoir 510, 520, 530, 540 when fluid is injected into the said reservoir 510, 520, 530, 540 via the respective first, second, third and fourth fill ports 512, 522, 532, 542. Also, the vents allow gas (e.g. air) to pass into the respective first to fourth reagent reservoirs 510, 520, 530, 540 when fluid is drawn out of the first to fourth reagent reservoirs 510, 520, 530, 540 to locations downstream within the reagent supply assembly 500.

Similarly, one vent per sample channel (624a - 624h) is provided on the top surface of the filter cartridge housing 101. Finally, a waste chamber fluid bath vent 151 is provided on a top surface of the filter cartridge housing 101.

Each vent (515, 525, 535, 545, 624a - 624h, 151) may comprise a membrane (not shown) configured to allow passage of gas but prevent passage of liquid. The membrane may comprise a hydrophobic membrane. The hydrophobic membrane may be applied with adhesive. The hydrophobic membrane may have a thickness in the region of 0.07 μηι.

Figures 5, 6, 7 show internal components of the filter cartridge 100. Figures 5 and 6 are cross sectional of views and Figure 7 shows the filter cartridge 100 with the top surface and related components removed. First, second, third and fourth reagent reservoirs 510, 520, 530, 540 are visible in Figure 7 and first reservoir outlet 513, second reservoir outlet 523 and third reservoir outlet 533 are also visible. First to eighth mixing chambers 620a - 620h are also visible. The eight filter assemblies 640a - 640h are visible within the waste chamber fluid bath 150.

Figure 9 shows internal components of the filter cartridge 100. In this figure, a bottom surface of the filter cartridge 100 is removed together with all features that would be beneath that surface including the valve actuators 1 11 - 1 16, the filter cartridge plinth 102 and the syringes 630a - 630h.

Figure 10 shows a cross-section through the filter cartridge 100 in which aspects of the eight channels a - h are visible in parallel.

Figures 1 1 to 22 show aspects of the filter assembly 640, as described in more detail below. It is not an essential feature of the filter cartridge 100 that the waste chamber serves as a fluid bath. It is also not an essential feature of the filter cartridge 100 that there is only one waste chamber for all eight channels (a - h). Figure 23 shows an alternative embodiment of analysis assembly 600. In this embodiment, it will be seen that there is no waste chamber fluid bath 150. Instead, the Figure 23 embodiment comprises a waste chamber 180 and a separate fluid bath 170. It may be the case that each channel (a - h) comprises its own waste chamber 180 or that all channels (a - h) share a single waste chamber 180 into which the waste from all channels (a - h) is received. The or each waste chamber 180 comprises a waste chamber vent 181.

It is also not an essential feature of the filter cartridge 100 that it comprises eight channels. Alternative filter cartridges may comprise more than eight channels or fewer than eight channels.

The filter cartridge housing 101 , and other components of the filter cartridge 100, may be manufactured from one or more plastics materials. Examples of materials that may be used include: acrylonitrile butadiene styrene (ABS); and amorphous blends of

polyphenylene ether resin and polystyrene (such as Noryl™).

Filter assembly of the first embodiment

A filter assembly 640 (of which there are eight in the filter cartridge 100), in accordance with a first embodiment, is shown in Figure 11. The filter assembly 640 comprises a first filter housing 641 (see Figure 12) contained within a first substantially circular portion 645 of the filter assembly 640 and a second filter housing 642 (again, see Figure 12) contained within a second substantially circular portion 646 of the filter assembly 640. The filter assembly 640 comprises a first side 647 and a second side 648. Figure 11 shows the filter assembly 640 in a direction facing an exterior of the first side 647. An interior of the first side 647 is shown in Figure 12 and an interior of the second side 648 is shown in Figure 14. The first side 647 comprises a first side upstream foot 647x and a first side downstream foot 647y. The first side 647 is supported on a bottom surface of the filter cartridge 100 by the first side upstream foot 647x and the first side downstream foot 647y. The second side 648 comprises a second side upstream foot 648x and a second side downstream foot 648y. The second side 648 is supported on a bottom surface of the filter cartridge 100 the second side upstream foot 648x and the second side downstream foot 648y.

Figure 12 shows the first side 647 with its feet 647x, 647y facing down while Figure 14 shows the second side 648 with its feet 648x, 648y facing up. The filter assembly 640 is formed when both sides 647, 648 are brought together with all feet 647x, 647y, 648x, 648y facing down, as shown in Figure 1 1.

The first filter housing 641 comprises a first cavity formed between the first side 647 and the second side 648. The first filter housing 641 has a substantially circular cross-section within the first substantially circular portion 645. The second filter housing 642 comprises a second cavity formed between the first side 647 and the second side 648. The second filter housing 642 has a substantially circular cross-section within the second substantially circular portion 646. The first filter housing 641 comprises a first internal surface 641 x in the first side 647 and a second internal surface 641 y in the second side 648. The first filter housing 641 is configured to accommodate a first substantially circular planar filter 643 between the first internal surface 641x and the second internal surface 641 y. The second filter housing 642 comprises a first internal surface 642x in the second side

648 and a second internal surface 642y in the first side 647. The second filter housing 642 is configured to accommodate a second substantially circular planar filter 644 between the first internal surface 642x and the second internal surface 642y. The internal surfaces 641 x, 641 y, 642x, 642y are provided with protrusions 665 and recesses 667, 668, 669. The protrusions and recesses, which sit either side of the relevant filter 643, 644 contribute to retaining the relevant filter 643, 644 in a fixed position within the relevant filter housing 641 , 642 whilst encouraging flow of fluid to extend across a wide area of the surface of the relevant filter 643, 644. This maximises a proportion of the area of the surface of the relevant filter 643, 644 that receives fluid to be filtered and so reduces the likelihood of filter blocking. Material that is sufficiently small to pass through the relevant filter 643, 644 proceeds to pass through it while material that is too large to pass through the relevant filter 643, 644 is retained across a wide area of the surface of the relevant filter 643, 644.

Figure 15 shows a cross section through the filter assembly 640 and a lower half of the filter assembly 640 below the cross section. A gap between an inmost extent of the protrusions 665 on the relevant first internal surface 641 x, 642x and an inmost extent of the surface on the second internal surface 641 y, 642y is configured to accommodate the relevant substantially planar filter 643, 644.

The first filter housing 641 comprises a first filter housing inlet 651 (as shown in Figure 13) that projects through the first side upstream foot 647x. The first filter housing inlet 651 enables flow of fluid into one side of the first filter housing 641 which facilitates flow of fluid onto a first side of the first filter 643.

The first internal surface 641x of the first filter housing 641 comprises a series of elongate distribution protrusions 665 defining elongate distribution recesses 667 there between. The elongate distribution recesses 667 project vertically up from the first side upstream foot 647x so as to encourage fluid to spread vertically up the first filter 643 (vertically up in the orientation of use, as shown in Figure 12).

The second internal surface 641 y of the first filter housing 641 comprises a combination of elongate collection channels 668 and radial collection channels 669 that together act to gather fluid that has passed through the first filter 643 towards a first filter housing outlet 652 (see Figure 20) that is located in a side face of the second side 648 of the filter assembly 640. The first filter housing outlet 652 is located towards a top side (in the orientation of use, as shown in Figure 12) of the first filter housing 641 opposite the feet 647x, 647y, 648x, 648y.

By arranging the first filter housing inlet 651 towards a lower side of the first filter housing 641 (near the feet 647x, 648x) and the first filter housing outlet 652 towards a higher side of the first filter housing 641 (opposite the feet 647x, 648x), fluid passing through the first filter housing 641 not only has to cross the first filter 643 but also has to transition the height of the first filter housing 641. On an external face of the second side 648 of the filter assembly 640 is a diagonal conduit 653 (see Figures 19 and 20) that is configured to provide fluid communication between the first filter housing outlet 652 and a second filter housing inlet 656 in the second filter housing 642. The diagonal nature of the diagonal conduit 653 means that is conveys fluid from a higher side of the first filter housing 641 to a lower side of the second filter housing 642.

Referring to Figures 19 and 20, the diagonal conduit 653 is located within a diagonal external recess 654 of the second side 648 of the filter assembly 640 and is enclosed by a diagonal cover portion 655.

The second filter housing 642 comprises the second filter housing inlet 656 towards a lower side (adjacent the second foot 648y) of the second filter housing 642 in the second side 648. The second filter housing 642 also comprises a second filter housing outlet 657 towards a higher side of the second filter housing 642 in the first side 647.

Referring to Figure 14, the first internal surface 642x of the second filter housing 642 comprises a series of elongate distribution protrusions 665 defining elongate distribution recesses 667 there between. The elongate distribution recesses 667 project vertically up so as to encourage fluid to spread vertically up the second filter 644 (vertically down in the orientation of Figure 14, which is opposite the orientation of use).

Referring to Figure 12, the second internal surface 642y of the second filter housing 642 comprises a combination of elongate collection channels 668 and radial collection channels 669 that together act to gather fluid that has passed through the second filter 644 towards the second filter housing outlet 657 that is located in a side face of the first side 647 of the filter assembly 640 towards the top (in the orientation of use). The second filter housing outlet 657 is located towards a top side of the second filter housing 642 opposite the feet 647y, 648y.

As with the first filter housing 641 , by arranging the second filter housing inlet 656 towards a lower side of the second filter housing 642 (near the feet 647y, 648y) and the second filter housing outlet 657 towards a higher side of the second filter housing 642 (opposite the feet 647y, 648y), fluid passing through the second filter housing 642 not only has to cross the second filter 644 but also has to transition the height of the second filter housing 642.

On an external face of the first side 647 of the filter assembly 640 is an exit conduit 658, as shown in Figure 18. The exit conduit 658 is configured to convey fluid from a higher side of the second filter housing 642 (opposite the first side downstream foot 647y) to a lower side of the second filter housing 642 (near the first side downstream foot 647y). The exit conduit 658 is configured to provide fluid communication between the second filter housing outlet 657 and an exit conduit link 659 that terminates in the first side downstream foot 647y. The exit conduit 658 is in fluid communication with the fourth conduit 614 of the filter cartridge 100 (see Figure 4).

Referring to Figures 17 and 18, the exit conduit 658 is located within a linear external recess 660 of the first side 647 of the filter assembly 640 and is enclosed by a linear cover portion 661.

A route for fluid through the filter assembly 640 is now described with reference to Figure 20 which shows an exterior surface of the second side 648 of the filter assembly 640 in solid lines and shows interior components of the filter assembly 640 in broken lines.

Fluid enters the filter assembly 640 through the first filter housing inlet 651 at a lower edge of the first filter housing 641. It flows both upwards within the first filter housing 641 (vertically up in the Figure 20 representation) and also across the first filter 643 (out of the plane of the paper in the Figure 20 representation). By entering at a lower face of the first filter housing 641 , fluid fills upwards and, by its movement, pushes gas out of the first filter housing 641 and onwards within the filter assembly 640. This is so as to avoid trapping air within the first filter housing 641.

Having passed through the first filter 643 and reached a higher part of the first filter housing 641 , fluid passes out through the first filter housing outlet 652 and into the diagonal conduit 653. The purpose of the diagonal conduit 653 is to transfer fluid from the first filter housing outlet 652 into the second filter housing 642 through the second filter housing inlet 656 which is located towards a lower edge of the second filter housing 642. Fluid entering the second filter housing 642 through the second filter housing inlet 656 flows both upwards within the second filter housing 642 (vertically up in the Figure 20 representation) and also across the second filter 644 (into the plane of the paper in the Figure 20 representation). By entering at a lower face of the second filter housing 642, fluid fills upwards and by its movement pushes gas out of the second filter housing 642 and onwards within the filter assembly 640. This is so as to avoid trapping air within the second filter housing 642.

Having passed through the second filter 644 and reached a higher part of the second filter housing 642, fluid passes out through the second filter housing outlet 657 and into an exit conduit 658 located in the first side 647 of the filter assembly 640. The purpose of the exit conduit 658 is to transfer fluid from towards a top edge of the second filter housing 642 towards a bottom edge of the filter assembly 640 and, via an exit conduit link 659, into the fourth conduit 614 of the filter cartridge 640 (see Figure 4).

Arrangement of filter assemblies within the filter cartridge of the first embodiment

As evident in Figures 7, 9 and 10, the eight filter housings 640a - 640h are located in parallel. Moreover, with reference to Figure 16, a centre of the eight first substantially circular portions 645a - 645h sits on an axis, A, that is parallel to all of the first to sixth valve actuator axes. Furthermore, a centre of the eight second substantially circular portions 646a - 646h sits on an axis, B, that is also parallel to all of the first to sixth valve actuator axes.

In this way, while the net direction of flow of fluid in each channel (a - h) within the cartridge 100 is parallel to the direction of the syringe axes, the orientation of the plane of each of the substantially planar filters 643a - 643h, 644a - 644h is in line with, rather than orthogonal to, the net direction of flow of fluid. Accordingly, a significantly more compact filter cartridge can be achieved than would be possible if the plane of each of the substantially planar filters 643a - 643h, 644a - 644h were not orthogonal to the net direction of fluid flow in each channel (a - h).

Moreover, in this way, the geometry of every channel can be identical to every other channel. By contrast, if the substantially planar filters were to be orthogonal to the net direction of flow of fluid in each channel then, for reasons of seeking a compact overall volume of filter cartridge, it would be necessary to stagger the positions of the filters which would mean that the geometry of each channel (a - h) would be different.

First embodiment in use - generic process

The filter cartridge 100 is configured to be received within an apparatus (not illustrated) comprising: first to eighth syringe drivers; first to sixth valve drivers; and a heat supply shoe. The apparatus is configured to receive the filter cartridge in such an orientation that the first to eighth syringe drivers are adjacent, respectively, the first to eighth syringe actuators 633a - 633h; the first to sixth valve drivers are adjacent, respectively, the first to sixth valve actuators 11 1 , 112, 113, 114, 1 15, 1 16; and the heat supply shoe is adjacent the thermal interface region 160.

The filter cartridge 100 may be supplied with the valve actuators in the initial positions, as described above and illustrated in Figure 1. In particular: the first valve actuator 1 11 is in its first position such that the selector valve 550 is closed to all four supply lines 514, 524, 534, 544; the second to sixth valve actuators 1 12, 1 13, 1 14, 1 15, 1 16 are each in their open position such that the mixing chamber valves 672, the analysis assembly entry valves 673, the filter assembly valves 674, the waste chamber valves 675 and the outlet valves 676 are all open (so as to avoid a potential build-up of pressure prior to use). Furthermore, the eight syringe actuators 633a - 633h are all in their respective inmost positions. The filter cartridge 100 may be supplied with the reagent reservoirs 510, 520, 530, 540 filled with their respective reagents. Alternatively, the reagents may be deposited into the respective reservoirs via the respective fill ports 512, 522, 532, 542 immediately prior to use. To begin use of the filter cartridge 100, each of the second to sixth valve actuators 112, 1 13, 114, 115, 116 is moved from its initial, inner, open position to its outer position such that the mixing chamber valves 672, the analysis assembly entry valves 673, the filter assembly valves 674, the waste chamber valves 675 and the outlet valves 676 are all closed. Subsequently, eight samples (of, for example, blood), one in each channel (a - h), may be injected into the respective mixing chambers 620a - 620h of the filter cartridge 100 via the respective sample inlets 621a - 621 h. In this way, each sample passes through its respective sample inlet filter assembly 622a - 622h and is thereby filtered by its respective sample inlet filter 623a - 623h (so as to trap large particles) before arriving at its respective mixing chamber 620a - 620h.

Once the eight samples are present in the mixing chambers 620a - 620h, the first valve actuator 1 11 is moved from its first position (in which the selector valve 550 is closed to all four supply lines 514, 524, 534, 544) into its second position. In the second position of the first valve actuator 1 1 1 , the selector valve 550 is open to first reservoir supply line 514 such that the first reservoir supply line 514 only is fluidly connected to the selector valve outlet conduit 560. At the same time as (or shortly before or shortly after), the third valve actuator 1 13 is moved from the closed position to the open position such that the eight analysis assembly entry valves 673a - 673h are opened. The second, and fourth to sixth valve actuators 112, 1 14, 1 15, 1 16 are left in the closed position such that their respective valves remain closed. All eight syringe actuators 633a - 633h are withdrawn simultaneously for all eight channels. This causes reagent to be drawn from the first reagent reservoir 510 into each syringe housing 631a - 631 h.

Once an appropriate volume of the first reagent has been drawn into each syringe housing 631 a - 631 h, the third valve actuator 1 13 is moved from its open position back to its closed position such that each of the analysis assembly entry valves 673a - 673h is closed. Then, the second valve actuator 1 12 is moved from its closed position to its open position such that each of the mixing chamber valves 672a - 672h is opened. All eight syringe actuators 633a - 633h are pushed inward such that reagent in the syringe housings 631a - 631 h is forced into the respective mixing chambers 620a - 620h where the samples are already present.

It may be that a volume of the first reagent required to be mixed with the sample in each of the mixing chambers 672a - 672h is less than a volume that can be accommodated in the respective syringe housings 631a - 631 h. Accordingly, in order to transfer sufficient volume of reagent, it may be necessary to repeat the cycle of transfer of reagent from the first reagent reservoir 510 into the eight mixing chambers 672a - 672h via the eight syringe housings 631a - 631 h multiple times.

Each step of transferring the first reagent into the eight respective syringe housings 631a - 631 h requires the following valve positions:

first valve actuator 11 1 in the second position such that the selector valve 550 is open to first reservoir supply line 514;

second valve actuator 1 12 in the closed position such that the mixing chamber valves 672a - 672h are closed;

third valve actuator 113 in the open position such that the analysis assembly entry valves 673a - 673h are open; and

fourth valve actuator 1 14 in the closed position such that the filter assembly valves 674a - 674h are closed.

The positions of the remaining valves are not relevant for this part in the procedure but it is most likely that the remaining valve actuators are in their closed positions and therefore the valves are closed.

With the valve actuators appropriately positioned, the first reagent is transferred into the eight respective syringe housings 631a - 631 h by simultaneously withdrawing all eight syringe actuators 633a - 633h. Each step of transferring the first reagent from the eight respective syringe housings 631a - 631 h into the eight respective mixing chambers 620a - 620h requires the following valve positions:

second valve actuator 1 12 in the open position such that the mixing chamber valves 672a - 672h are open;

third valve actuator 1 13 in the closed position such that the analysis assembly entry valves 673a - 673h are closed; and

fourth valve actuator 1 14 in the closed position such that the filter assembly valves 674a - 674h are closed. The positions of the remaining valves are not relevant for this part in the procedure but it is likely that the first valve actuator 1 11 is in the third position such that selector valve 550 is closed and the remaining valve actuators are in their closed positions and therefore the valves are closed.

With the valve actuators appropriately positioned, the fluid is transferred from the eight respective syringe housings 631a - 631 h into the eight respective mixing chambers 640a - 640h by simultaneously pushing inward all eight syringe actuators 633a - 633h. Once sufficient volume of the first reagent is present in the mixing chambers 620a - 620h, there is an optional step of drawing fluid from each of the mixing chambers 620a - 620h into the syringe bodies 631a - 631 h and back again into the mixing chambers 620a - 620h in order that mixing of the reagent fluid with the samples is improved. The improved mixing may be caused by turbulence in the fluid in the mixing chamber caused by re-entry of a portion of the fluid into the mixing chambers 620a - 620h from the syringe bodies 631a - 631 h. This cycle of transfer of fluid between the mixing chambers 620a - 620h and the syringe bodies 631a - 631 h may be repeated as many times as is necessary to achieve the required confidence in the mixing of the samples with the first reagent. Once sufficient mixing has been achieved, the syringes 630a - 630h are used to transfer the mixed fluid in mixing chambers 620a - 620h into the waste chamber fluid bath 150 via the filter assemblies 640a - 640h. The volume of fluid to be transferred in each channel may be more than the capacity of each syringe 620a - 620h. Accordingly, it may be necessary to effect the transfer in a number of stages. In one stage, fluid is transferred from the mixing chambers 620a - 620h to the syringe housings 631a - 631 h. This is achieved by the following valve positions: second valve actuator 1 12 in the open position such that the mixing chamber valves 672a - 672h are open;

third valve actuator 113 in the closed position such that the analysis assembly entry valves 673a - 673h are closed; and

fourth valve actuator 1 14 in the closed position such that the filter assembly valves 674a - 674h are closed. The positions of the remaining valves are not relevant for this part in the procedure but it is most likely that the first valve actuator 11 1 is in the third position such that selector valve 550 is closed and the remaining valve actuators are in their closed positions and therefore the valves are closed.

Subsequently, fluid is transferred from the syringe housings 631a - 631 h into the waste chamber fluid bath 150 via the filter assemblies 640a - 640h. This is achieved by the following valve positions: second valve actuator 1 12 in the closed position such that the mixing chamber valves 672a - 672h are closed;

third valve actuator 1 13 in the closed position such that the analysis assembly entry valves 673a - 673h are closed;

fourth valve actuator 1 14 in the open position such that the filter assembly valves 674a - 674h are open;

fifth valve actuator 1 15 in the open position such that the waste chamber valves 675a - 675h are open; and

sixth valve actuator 1 16 in the closed position such that the outlet valves 676a - 676h are closed.

The positions of the first valve actuator 1 11 is not material for this step but it is likely to be in the third position such that selector valve 550 is closed.

The procedure of transferring fluid from the mixing chambers 620a - 620h to the waste chamber fluid bath 150 via the syringes 630a - 630h is repeated as many times as is necessary to transfer the necessary volume of fluid.

The principle purpose of transferring the fluid to the waste chamber is to force the mixture of first reagent and through the filter assemblies 640a - 640h. As discussed previously, the filter assemblies 640a - 640h each comprise a first filter housing 641a - 641 h including a first filter 643 and a second filter housing 642a - 642h comprising a second filter 644. The first filter 643 is intended to prevent passage of large components within fluid mixture while the second filter 644 may prevent passage of smaller pieces within fluid mixture. In a subsequent stage of the process, the second reagent (from the second reagent reservoir 520) is passed into and through the filter assemblies 640a - 640h, via the syringes 630a - 630h, in order to act upon the contents left following the filtration of the mixture of sample and first reagent.

Movement of the second reagent into the syringes 630a - 630h is achieved by the following valve positions: first valve actuator 1 11 in the fourth position such that the selector valve 550 is open to second reservoir supply line 524;

third valve actuator 1 13 in the open position such that the analysis assembly entry valves 673a - 673h are open; and

fourth valve actuator 1 14 in the closed position such that the filter assembly valves

674a - 674h are closed.

The positions of the fifth valve actuator 115 and the sixth valve actuator 116 are not material for this step but they are likely to be in their closed positions such that the waste chamber valves 675a - 675h and the outlet valves 676a - 676h are closed.

With the valve actuators appropriately positioned, the second reagent is transferred into the eight respective syringe housings 631a - 631 h by simultaneously withdrawing all eight syringe actuators 633a - 633h.

Movement of fluid from the syringes 630a - 630h into the filter assemblies 640a - 640h is achieved by the following valve positions: second valve actuator 1 12 in the closed position such that the mixing chamber valves 672a - 672h are closed;

fourth valve actuator 1 14 in the open position such that the filter assembly valves 674a - 674h are open; fifth valve actuator 1 15 in the open position such that the waste chamber valves 675a - 675h are open; and

The positions of the first valve actuator 11 1 is not material for this step but it is likely to be in the fifth position such that selector valve 550 is closed.

With the valve actuators appropriately positioned, the fluid is transferred from the eight respective syringe housings 631a - 631 h into the eight respective filter assemblies 640a- 640h by simultaneously pushing inward all eight syringe actuators 633a - 633h.

In the event that a volume of the second reagent to be forced into the filter assemblies 640a - 640h is less than a volume that can be accommodated in the respective syringe housings 631a - 631 h, it may be necessary to repeat the cycle of transfer of reagent from the second reagent reservoir 520 into the eight filter assemblies 640a - 640h via the eight syringe housings 631 a - 631 h multiple times.

In a subsequent stage of the process, the third reagent (from the third reagent reservoir 530) is passed into and through the filter assemblies 640a - 640h, via the syringes 630a - 630h, in order to act upon the contents left following the action of the second reagent on the content of the filter assemblies.

Movement of the third reagent into the syringes 630a - 630h is achieved by the following valve positions: first valve actuator 1 11 in the sixth position such that the selector valve 550 is open to third reservoir supply line 534;

fourth valve actuator 1 14 in the closed position such that the filter assembly valves 674a - 674h are closed. The positions of the fifth valve actuator 115 and the sixth valve actuator 116 are not material for this step but they are likely to be in their closed positions such that the waste chamber valves 675a - 675h and the outlet valves 676a - 676h are closed. With the valve actuators appropriately positioned, the third reagent is transferred into the eight respective syringe housings 631a - 631 h by simultaneously withdrawing all eight syringe actuators 633a - 633h.

Movement from the syringes 630a - 630h into the filter assemblies 640a - 640h is achieved by the following valve positions: second valve actuator 1 12 in the closed position such that the mixing chamber valves 672a - 672h are closed;

third valve actuator 113 in the closed position such that the analysis assembly entry valves 673a - 673h are closed;

sixth valve actuator 1 16 in the closed position such that the outlet valves 676a -

676h are closed.

The position of the first valve actuator 11 1 is not material for this step but it is likely to be in the seventh position such that selector valve 550 is closed.

With the valve actuators appropriately positioned, the fluid is transferred from the eight respective syringe housings 631a - 631 h into the eight respective filter assemblies 640a- 640h by simultaneously pushing inward all eight syringe actuators 633a - 633h. In the event that a volume of the third reagent to be forced into the filter assemblies 640a - 640h is less than a volume that can be accommodated in the respective syringe housings 631 a - 631 h, it may be necessary to repeat the cycle of transfer of reagent from the third reagent reservoir 530 into the eight filter assemblies 640a - 640h via the eight syringe housings 631a - 631 h multiple times. In a subsequent stage of the process, the fourth reagent (from the fourth reagent reservoir 540) is passed into and through the filter assemblies 640a - 640h, via the syringes 630a - 630h, in order to act upon the contents left following the action of the third reagent on the content of the filter assemblies.

Movement of the fourth reagent into the syringes 630a - 630h is achieved by the following valve positions: first valve actuator 1 11 in the eighth position such that the selector valve 550 is open to fourth reservoir supply line 544;

second valve actuator 112 in the closed position such that the mixing chamber valves 672a - 672h are closed;

674a - 674h are closed.

With the valve actuators appropriately positioned, the fourth reagent is transferred into the eight respective syringe housings 631a - 631 h by simultaneously withdrawing all eight syringe actuators 633a - 633h.

The position of the first valve actuator 11 1 is not material for this step but it is likely to be in the ninth position such that selector valve 550 is closed.

In the event that a volume of the fourth reagent to be forced into the filter assemblies 640a - 640h is less than a volume that can be accommodated in the respective syringe housings 631 a - 631 h, it may be necessary to repeat the cycle of transfer of reagent from the fourth reagent reservoir 540 into the eight filter assemblies 640a - 640h via the eight syringe housings 631a - 631 h multiple times.

In a final stage of the process, a volume of fluid passes through the second filters 644a - 644h and is output via the sample outlets 690a - 690h to the receptacles 691a - 691 h. This is achieved by the following valve positions: second valve actuator 1 12 in the closed position such that the mixing chamber valves 672a - 672h are closed;

fifth valve actuator 1 15 in the closed position such that the waste chamber valves 674a - 674h are closed; and

sixth valve actuator 1 16 in the open position such that the outlet valves 676a - 676h are open.

The position of the first valve actuator 1 11 is not material for this step but it is likely to be in the ninth position such that selector valve 550 is closed. In general, at each stage in the process, movement of valve actuators 1 11 , 1 12, 1 13, 114, 1 15, 1 16 is not undertaken at the same time as movement of syringe actuators 633a - 633h. Rather, the valves actuators 11 1 , 112, 113, 114, 115, 116 are first set to the appropriate positions for a particular step and only then is fluid drawn into or out of the syringes 631a - 633h by movement of the syringe actuators 633a - 633h.

In one exception to this, it may be that the fluid that is output via the sample outlets 690a - 690h to the receptacles 691a - 691 h is diverted mid-stream from flow that is otherwise routed to the waste chamber fluid bath 150. This may be achieved by actuating the fifth and sixth valve actuators 115, 1 16 during actuation of the syringe actuators 633a - 633h. More specifically, at the start of a final actuation of the syringe actuators 633a - 633h, the fifth valve actuator 115 may be in the open position (such that the waste chamber valves 675a - 675h are open) and the sixth valve actuator 1 16 may be in the closed position (such that the outlet valves 676a - 6765h are closed). Then, part-way through the final actuation of the syringe actuators 633a - 633h, the positions of the fifth and sixth valve actuators 1 15, 116 may reverse (such that the waste chamber valves 675a - 675h are closed the outlet valves 676a - 6765h are open). Then, still further through the final actuation of the syringe actuators 633a - 633h, the positions of the fifth and sixth valve actuators 1 15, 1 16 may reverse back (such that the waste chamber valves 675a - 675h are open the outlet valves 676a - 6765h are closed).

Once fluid has been output to the receptacles 691a - 691 h, the syringe actuators 633a - 633h come to rest in their inmost positions. Subsequently, the first valve actuator 11 1 is returned to its first position and the remaining valve actuators 112, 1 13, 1 14, 115, 116 are all returned to their inmost positions. In this way, the filter cartridge 100 returns to its original state with respect to valve actuator and syringe actuator positions, wherein all actuators are within the filter cartridge plinth 102. The filter cartridge 100 may then be removed from the apparatus and stored or disposed of in a safe manner.

At any particular point in the process as described, it may be appropriate for the

temperature of fluid at that time present in the filter assemblies 640a - 640h to be changed or otherwise controlled. Control of the temperature of the fluid in the filter assemblies 640a - 640h is achieved by controlling the temperature of fluid in the waste chamber fluid bath 150. Accordingly, in an embodiment that is not provided with fluid already present in the waste chamber prior to use, this may be achieved only once sufficient fluid has passed into the waste chamber fluid bath 150. Heat may be supplied by an external heat source, via the thermal interface region 160 to the fluid present in the waste chamber fluid bath 150. The fluid present in the waste chamber fluid bath 150 surrounds the filter assemblies 640a - 640h and, as such, heat is transferred from the fluid in the waste chamber fluid bath 150, through the walls of the filter assemblies 640a - 640h and to the fluid inside the filter assemblies 640a - 640h. In terms of timing, it may be that the heat is applied only once the fluid to be heated is present within the filter assemblies 640a - 640h. Alternatively, it may be that the fluid in the waste chamber fluid bath 150 is pre-heated before the arrival in the filter assemblies 640a - 640h of the fluid that is ultimately intended to be heated.

First embodiment in use - blood lysis application

In a specific application, the sample is a blood culture sample and the filter cartridge 100 is used for lysing blood and seeking to isolate biological elements (in particular

microorganisms such as bacteria or fungi from viable pathogen microorganisms), that may or may not be present in that blood, for subsequent testing.

In this application, the purpose of the first reagent is to selectively lyse the blood to an extent that the blood cell membranes are broken and the intra-cellular components are released, while not lysing any microorganisms found in the blood.

Once sufficient mixing of the blood sample with the first reagent has been carried out, as described above, the mixture is passed through the filter assembly 640a - 640h. The first filter 643a - 643h is selected to prevent passage of blood clots and cell debris (e.g. large pieces of cell membrane) whilst allowing passage of any microorganisms found in the blood (together with smaller components of the lysed blood, such as intracellular enzymes).

The second filter 644a - 644h is selected to retain microbial cells present in the lysed blood. The purpose of the second reagent is to inactivate enzymes released from the lysed blood and retained in the filter assembly 640a - 640h. The second reagent may be left in contact with the lysed blood for a specific period, for example for around five minutes. The second reagent may have a high pH by which enzymes are inactivated.

The purpose of the third reagent is to neutralise the second reagent so as to prevent damage to microbial cells that may be present. The third reagent may be a buffer to restore a neutral pH , or at least to reduce the high pH of the second reagent. The purpose of the fourth reagent is to lyse microbial cells that may be present and optionally to provide a substrate that can be acted upon by the intracellular enzymes released during microbial lysis.

The fluid that is output from the filter cartridge 100 may then be tested for the presence of microbial enzymes that may or may not be present. In this way, the filter cartridge 100 may facilitate detection of the presence or absence of, and potentially also identify, bacterial and/or fungal microbes in blood.

Filter cartridge of a second embodiment

A second embodiment of a filter cartridge 100' in accordance with the invention is illustrated in Figure 24. This embodiment again comprises eight independent channels (a, b, c, d, e, f, g, h) for analysing eight samples.

To avoid unnecessary repetition, those features of the second embodiment 100' that are the same (physically and/or functionally) as those of the first embodiment 100 are not described again. Rather, the description focuses on those features of the second embodiment 100' that differ from those of the first embodiment 100.

The most apparent difference is the nature of the filter assembly 640', of which, as in the first embodiment 100, there are eight located in parallel. In the second embodiment 100', the filter assembly 640' comprises one filter housing 641 ' as shown in Figure 29 (in place of the first filter housing 641 and the second filter housing 642 of the first embodiment as shown in Figure 13) and, more schematically, in Figure 31. The filter housing 641' (see Figure 29) is contained within a portion 645' of the filter assembly 640' that is substantially square.

The filter assembly 640' comprises a first side 647' and a second side 648'. Figure 29 shows the filter assembly 640' in a direction facing an exterior of the first side 647'.

The first side 647' comprises an exterior face plate 6471 and a perimeter portion 6472 perpendicular to the exterior face plate 6471. The second side 648' comprises an exterior face plate 6481 and a perimeter portion 6482 perpendicular to the exterior face plate 6481. The perimeter portions 6472, 6482 of the first and second sides 647', 648' together form a continuous or substantially continuous edge 649.

The first side 647' comprises a first side foot 647x'. The first side 647' is supported on a bottom surface located on a lower portion of the edge 649 of the filter cartridge 100' by the first side foot 647x'. The second side 648 comprises a second side foot 648x'. The second side 648' is supported on a bottom surface located on a lower portion of the edge 649 of the filter cartridge 100' by the second side foot 648x'.

The filter assembly 640' is formed when both sides 647', 648' are brought together with the first side foot 647x' facing down and the second side foot 648x' facing down, as shown in Figure 29.

The filter housing 641' comprises a cavity formed between the first side 647' and the second side 648'. The first filter housing 641 has a substantially circular cross-section within the substantially square portion 645'.

The filter housing 641 ' comprises a first internal surface in the first side 647' and a second internal surface in the second side 648'. The first and second internal surfaces may be substantially mutually parallel. The first filter housing 641 is configured to accommodate a substantially circular planar filter 643' between the first internal surface and the second internal surface. Accordingly, the filter assembly 640' may comprise first and second mutually parallel internally surfaces both parallel to exterior mutually parallel face plates 6471 , 6481. The edge 649 may be substantially perpendicular to the parallel planes of the internal surfaces and the exterior face plates 6471 , 6481.

In the embodiment of Figure 29, the first and second mutually parallel exterior face plates 6471 , 6472 are substantially square with two of four corners radiused while the mutually parallel internally surfaces are substantially circular as evident from Figure 30. In alternative embodiments, the first and second mutually parallel exterior face plates may be circular or substantially circular. For example, the exterior form of the filter assembly 640' may be geometrically similar to the exterior of a single one of the two filter housings 641 , 642 of the embodiment shown in Figure 11. The internal surfaces may be provided with protrusions 665 and recesses 667, 668, 669 as in the first embodiment.

The filter housing 641 ' comprises a filter housing inlet 651 that projects through the first side foot 647x'. The filter housing inlet 651 enables flow of fluid into one side of the filter housing 641 ' which facilitates flow of fluid onto a first side of the filter 643'.

The first internal surface 641x of the filter housing 641 ' comprises a series of elongate distribution protrusions 665 defining elongate distribution recesses 667 there between, as already illustrated in respect of the first embodiment. The elongate distribution recesses 667 project vertically up from the first side foot 647x' so as to encourage fluid to spread vertically up the filter 643' (vertically up in the orientation of use).

The second internal surface 641 y of the filter housing 641 ' comprises a combination of elongate collection channels 668 and radial collection channels 669 that together act to gather fluid that has passed through the filter 643' towards a filter housing outlet 652 that is located in a side face of the second side 648' of the filter assembly 640'. The filter housing outlet 652 is located towards a top side (in the orientation of use) of the filter housing 641 ' opposite the feet 647χ', 648x'. As in the first embodiment, by arranging the filter housing inlet 651 ' towards a lower side of the filter housing 641 ' (near the foot 647x') and the filter housing outlet 652' towards a higher side of the filter housing 641 ' (opposite the foot 647x), fluid passing through the filter housing 641 ' not only has to cross the filter 643' but also has to transition the height of the filter housing 641 '.

On an external face of the second side 648' of the filter assembly 640' is an exit conduit 658'. The exit conduit 658' is configured to convey fluid from a higher side of the filter housing 641 ' (opposite the second side foot 648x') to a lower side of the filter housing 641 ' (near the second side foot 648x'). The exit conduit 658' is configured to provide fluid communication between the filter housing outlet 652' and an exit conduit link 659 that terminates in the second side foot 648x'. The exit conduit 658' is in fluid communication with the fourth conduit 614 of the filter cartridge 100' (see Figure 31). A route for fluid through the filter assembly 640' is now described. Fluid enters the filter assembly 640' through the filter housing inlet 651 ' at a lower edge of the filter housing 641 '. It flows both upwards within the filter housing 641 ' and also across the filter 643'. By entering at a lower face of the filter housing 641 ', fluid fills upwards and, by its movement, pushes gas out of the filter housing 641 ' and onwards within the filter assembly 640'. This is so as to avoid trapping air within the filter housing 641 '.

Having passed through the filter 643' and reached a higher part of the filter housing 641 ', fluid passes out through the filter housing outlet 652' and into the exit conduit 658'. The purpose of the exit conduit 658' is to transfer fluid from towards a top edge of the filter housing 641 ' towards a bottom edge of the filter assembly 640' and, via an exit conduit link 659, into the fourth conduit 614 of the filter cartridge 100 (see Figure 31 for schematic representation). As in the first embodiment, the fourth conduit 614 bifurcates to form a fifth conduit 615 and a sixth conduit 616 (see Figure 31). The fifth conduit 615 is configured to connect the fourth conduit 614 to the waste chamber fluid bath 150. In the fifth conduit 615, upstream of the waste chamber fluid bath 150, is a waste chamber valve 675. The waste chamber valve 675 is configured to allow or prevent flow of fluid into the waste chamber fluid bath 150. Referring to Figures 25, 32 and 33, it can be seen that, as in the first embodiment, the waste chamber fluid bath 150 is a single waste chamber fluid bath 150 shared by all channels (a - h). Also as in the first embodiment, each channel (a - h) has its own waste chamber valve 675a - 675h. Downstream of each waste chamber valve 675a - 675h, each fifth conduit 615a - 615h opens into the single waste chamber fluid bath 150.

Downstream of each waste chamber valve 675a - 675h, each fifth conduit 615a - 615h of the second embodiment comprises a vertical channel 680a - 680h having an open upper end 692a - 692h in the orientation of use. The vertical channels 680a - 680h form part of a wall 699 that provides a boundary between the single waste chamber fluid bath 150 and an overflow vessel 682. A vertical notch 681 a - 681 h is present in each vertical channel 680a - 680h on a side of the wall 699 adjacent the waste chamber fluid bath 150 such that, in the orientation of use, fluid flowing to the top of each vertical channel 680a - 680h flows through the vertical notch 681 a - 681 h into the waste chamber fluid bath 150.

Referring to Figure 33, the wall 699 comprises portions 698 between the vertical channels 680a - 680h. Each of these portions 698 includes a vertical slit 697 that extends, in the orientation of use, vertically below the lowermost point of the vertical notches 681 a - 681 h. Accordingly, a lowest portion of the vertical slits 697 represents a lowest part of the boundary between the waste chamber fluid bath 150 and the overflow vessel 682.

Accordingly, in the event that a volume of fluid in the waste chamber fluid bath 150 reaches the lowest portion of the vertical slits 697 then fluid flows through the vertical slits 697 and into the overflow vessel 682. Since the lowest portion of the vertical slits 697 represents a lowest part of the boundary of the waste chamber fluid bath 150 (and is lower than the lowermost point of the vertical notches 681 a - 681 h) this prevents fluid from flowing back into the vertical channels 680a - 680h if the waste chamber fluid bath 150. Furthermore, this prevents cross-contamination between the different channels a - h.

In short, the design is such that fluid flowing out of the vertical channels 680a - 680h flows into the waste chamber fluid bath 150 and fluid overflowing out of the waste chamber fluid bath 150 flows into the overflow vessel 682. Having a maximum volume of fluid in the waste chamber fluid bath 150 may allow for greater control of the temperature of the fluid in the waste chamber fluid bath 150 because the volume of fluid in the fluid bath waste chamber 150 is fixed. Other differences between the first and second embodiments include that the second embodiment does not have inlet conduit 51 1 , 521 , 531 , 541 that protrude above a top surface of the filter cartridge housing 101 '. Instead, first, second, third and fourth fill ports 512, 522, 532, 542 are flush with a top surface of the filter cartridge housing 101'. A further difference between the first and second embodiment is that the second embodiment does not include mixing chamber vents 624a - 624h that are separate from the sample inlets 621a - 621 h. Rather, the sample inlets 621a - 621 h themselves also serve the purpose of mixing chamber vents. Alternatives

The skilled person recognises that not all of the features of the first and second

embodiments are essential to the invention. For example, the invention is not limited to a filter cartridge comprising eight channels. In addition, the invention is not limited to a filter cartridge comprising four reagent reservoirs. In addition, the invention is not limited to the exact arrangement of valves and conduits described herein. Alternatives are contemplated that fall within the scope of the claims.

Furthermore, applications of the filter cartridges described herein are broader than the blood lysis application described above. The filter cartridges disclosed herein may have alternative applications for isolating components of samples through a combination of chemical treatment and filtration.

In the first and second embodiments, the filter assembly 640a - 640h of each and every channel a - h is aligned with the filter assembly 640a - 640h of each and every other channel a - h and a primary filtration plane (that is, the plane of the first filter) of each and every channel a - h is parallel to the primary filtration plane of each and every other channel a - h. In alternatives to the first and second embodiments, not illustrated, it may be that a first half of the channels are aligned and second half of the channels are aligned but shifted laterally relative to the first half. The first half of the channels may alternate with the second half of the channels. In this way, the filter assemblies of the first half may, for example, be further towards one end of the filter cartridge while the filter assemblies of the second half may be further towards an opposite end of the filter cartridge. This may enable a larger number of channels to be incorporated into a filter cartridge of the same width. Indeed, in the second embodiment, the first to eighth sample inlets 621 a - 621 h are staggered with the first, third, fifth and seventh sample inlets 621 a, 621c, 621e, and 621g being shifted along a length of the cartridge 100' relative to the second, fourth, sixth and eighth sample inlets 621 b, 621 d, 621 f, and 621 h. This enables a width of the cartridge to be minimised.

The disclosure includes a large range of features that are not essential to either the first or second specific embodiments or to the invention as defined by the claims.

For example, optional features include that the first, second, third and fourth fill ports 512, 522, 532, 542 of the first embodiment protrude above a top surface of the filter cartridge housing 101. In alternative embodiments, the fill ports may be flush with a top surface of the filter cartridge. Similarly, the first to eighth sample inlets 621 a - 621 h need not protrude above a top surface of the filter cartridge housing 101. Indeed, it is possible that one or more of the fill ports and the sample inlets may be recessed with respect to a top surface of the filter cartridge housing 101.

Furthermore, referring to Figures 4, 23 and 31 , the location of the sample inlet filter assemblies 622a - 622h might be immediately downstream of the mixing chambers 620a - 620h (and upstream of the mixing chamber valves 672a - 672h) rather than immediately upstream of the mixing chambers 620a - 620h.

In addition, as in the second embodiment, it may be that in the first embodiment there is no mixing chamber vent 624a - 624h that is separate from the sample inlet 621 a - 621 h. In other words, the sample inlet 621 a - 621 h may also serve the purpose of a mixing chamber vent.

Furthermore, the external shape of the each filter housing 641 , 642, 641 ' and the internal shape of the cavity within said filter housing (configured to receive a filter 643, 643') are not limited to those illustrated. In the first embodiment, the external shape of the first and second filter housings 641 , 642 and the cavity within them are substantially circular. In the second embodiment, the external shape of the filter housing 641' is substantially square while the cavity within is substantially circular. The invention is not limited to any particular shape of filter housing or cavity. It is simply the case that the cavity is configured to receive a filter of an appropriate size and filtration capacity to perform the desired function.

It should also be noted that the combined waste chamber fluid bath 150 is applicable to embodiments that involve no filtering. The concept of a combined waste chamber fluid bath is applicable, for example, to any chamber whether or not configured or intended for filtration functionality. For example, a chamber located in a combined waste chamber fluid bath may be for conduction of a chemical reaction with or without filtration.

While in the illustrated embodiments both of the interior surfaces of the filter housing are provided with protrusions and/or recesses, it may be that only one of the interior surfaces is provided with protrusions and/or recesses. For example, it may be that protrusions and/or recesses are provided only on the outlet side internal surface. Alternatively, there may be no protrusions and/or recesses on either side. In general, protrusions and/or recesses may increase the volume of fluid required to fill the filter housing which may be undesirable. On the other hand, protrusions and/or recesses may encourage flow of fluid through the filter housing in an appropriate direction which may be beneficial for maximising use of the full area of the filter.

In order to reduce likelihood of damage in transit and/or to provide a convenient visual check, a filtration device in accordance with the disclosure may be shipped with each of the first to sixth valve actuators in its inmost position. As explained above, in the first embodiment the inmost position of the second, fourth, fifth and sixth valve actuators 112, 1 14, 115, 116 corresponds to an open position for the valves controlled by those actuators while the inmost position of the first and third valve actuators 1 11 , 1 13 corresponds to a closed position for the valves controlled thereby. However, this is not a requirement of the claimed invention. It may be the case, for example, that when each of the valve actuators is in its inmost position, the valves controlled by those actuators are all closed.

The specific illustrated embodiments comprise a thermal interface region for transfer of thermal energy from outside the waste chamber fluid bath to inside the waste chamber fluid bath. As the skilled person will readily appreciate, however, it is not essential that energy i transferred into the waste chamber fluid bath in the form of heat. Rather, it is only necessary that energy is transferred for the purpose of heating the contents of the waste chamber fluid bath. Accordingly, the thermal interface region may be substituted with an alternative energy transfer element.

For example, instead of a thermal interface region, it may be appropriate to have an interface region that enables transfer of energy in the form of infra-red radiation for the purposes of heating the contents of the waste chamber fluid bath.

In a further alternative, it may be appropriate to substitute the interface region with an energy transfer element that includes a conductor configured to receive electro-magnetic energy by electro-magnetic induction in order to heat the contents of the waste chamber fluid bath.

As the skilled person would also appreciate, transfer of energy for heating the contents of the waste chamber fluid bath may be by a combination of two of more of those techniques described here.

Claims

CLAIMS:

1. A filter housing comprising:

2. The filter housing of claim 1 wherein the inlet aperture is located in the first one of the pair of opposing sides.

3. The filter housing of claim 1 or claim 2 wherein the outlet aperture is located in the second one of the pair of opposing sides.

4. The filter housing of any preceding claim wherein the filtration chamber is substantially disc-shaped and the edge is substantially cylindrical.

5. The filter housing of claim 4 wherein the inlet aperture is located at or towards a first peripheral location of the disc-shaped filtration chamber and the outlet aperture is located at or towards a second peripheral location of the disc-shaped filtration chamber.

6. The filter housing of any preceding claim wherein the inlet conduit and the outlet conduit are mutually parallel or substantially mutually parallel.

7. The filter housing of any preceding claim further comprising a plinth configured to support the filter housing in a support plane in an orientation of use such that the filter support location lies in a filter plane that is perpendicular, or substantially perpendicular, to the support plane.

8. The filter housing of any preceding claim wherein one or both of the inlet and outlet conduits are parallel to the filter plane.

9. The filter housing of claim 7 or claim 8 wherein the inlet aperture is located in a portion of the filter housing closest to the plinth.

10. The filter housing of any of claims 7 to 9 wherein the outlet aperture is located in a portion of the filter housing furthest from the plinth.

1 1. The filter housing of any preceding claim further comprising a diagonal channel between the outlet aperture and the outlet conduit.

12. The filter housing of any preceding claim wherein the pair of opposing sides comprise a plurality of recesses and/or protrusions that are configured to facilitate flow of fluid within the filtration chamber from a vicinity of the inlet aperture and towards a vicinity of the outlet aperture.

13. A multi-channel filtration device comprising a plurality of filter housings of any preceding claim wherein the filter support location of each filter housing is parallel to the filter support location of each other filter housing.

14. The multi-channel filtration device of claim 13 wherein the inlet conduit of each filter housing is parallel to the inlet conduit of each other filter housing.

15. The multi-channel filtration device of claim 13 or claim 14 wherein the outlet conduit of each filter housing is parallel to the outlet conduit of each other filter housing.